This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This project contains three major sections that explore macromolecular interactions in living systems. First, we investigate how macromolecular crowding and confinement effects on protein dynamics. The second project aims to simulate how macromolecular interactions are mediated by water molecules in nano-sized systems. In the third project we focus on how the curvature of biological membranes is induced by peptides in a crowded medium. Multi-grained models that include both fine-grained (all-atom) and coarse-grained models are used in our projects. Sampling of the system is expedited by incorporating a start-of-the-art technique, the Replica-exchange method (REM, which integrates high-performance computing resources very efficiently.